Puma Predation Research Articles

Predation and Biophysical Context Control Long-Term Carcass Nutrient Inputs in an Andean Ecosystem

Animal carcass decomposition is an often-overlooked component of nutrient cycles. The importance of carcass decomposition for increasing nutrient availability has been demonstrated in several ecosystems, but impacts in arid lands are poorly understood. In a protected high desert landscape in Argentina, puma predation of vicuñas is a main driver of carcass distribution. Here, we sampled puma kill sites across three habitats (plains, canyons, and meadows) to evaluate the impacts of vicuña carcass and stomach decomposition on soil and plant nutrients up to 5 years after carcass deposition. Soil beneath both carcasses and stomachs had significantly higher soil nutrient content than adjacent reference sites in arid, nutrient-poor plains and canyons, but not in moist, nutrient-rich meadows. Stomachs had greater effects on soil nutrients than carcasses. However, we did not detect higher plant N concentrations at kill sites. The biogeochemical effects of puma kills persisted for several years and increased over time, indicating that kills do not create ephemeral nutrient pulses, but can have lasting effects on the distribution of soil nutrients. Comparison to broader spatial patterns of predation risk reveals that puma predation of vicuñas is more likely in nutrient-rich sites, but carcasses have the greatest effects on soil nutrients in nutrient-poor environments, such that carcasses increase localized heterogeneity by generating nutrient hotspots in less productive environments. Predation and carcass decomposition may thus be important overlooked factors influencing ecosystem functioning in arid environments.

Puma predation on Magellanic penguins: An unexpected terrestrial-marine linkage in Patagonia

The global loss of top predators has led to widespread changes in food webs. In Patagonia, it is hypothesized that local extirpations of terrestrial predators, including the puma (Puma concolor), has led to the expansion of Magellanic penguin (Spheniscus magellanicus) colonies across the Atlantic coast of Argentina. Interestingly, more recent wildlife conservation efforts in the region have led to an unexpected trophic link between pumas and penguins. Here, we used a camera trap array to assess this novel predator-prey relationship between pumas and penguins in Monte León National Park (MLNP) over a three-month period. Pumas were detected 12.5 times more than any other mammalian predator and were detected on 95% of the days during our study period. We also observed 28 individual events of pumas preying upon penguins. Our work demonstrates a strong linkage between the marine and terrestrial ecosystem at MLNP. Puma predation of penguins may have widespread ecological implications including effects on puma and penguin abundance, changes in puma social behavior, and interspecific competition among other prey items and carnivores in the park. We propose hypotheses and questions to investigate these potential outcomes.

Predation on livestock and its influence on tolerance toward pumas in agroecosystems of the Argentine Dry Chaco

ABSTRACT As an apex predator, pumas (Puma concolor) frequently enter into conflict with humans because of predation on livestock. We analyzed the association between puma predation and human tolerance in six agroecosystems of the Argentine Dry Chaco, a global deforestation hotspot. Specifically, we addressed attitudes and behaviors of local social actors toward pumas, their association to reported livestock predation, and the incidence of livestock management and puma abundance on predation on livestock. Puma predation on livestock was considered an important cause of livestock loss. Attitudes toward pumas were negative, but were not strongly associated with predation. However, retaliatory hunting was more common among respondents who experienced livestock predation. Breeding goats and sheep and the lack of corrals increased livestock predation probability, which decreased with low puma abundance. Tolerance toward pumas is low in agroecosystems of this region, and further qualitative studies should address its likely hidden causes.

Mountain goat survival and mortality during a period of increased puma abundance in the Black Hills, South Dakota.

We investigated survival and cause-specific mortality for a mountain goat (Oreamnos americanus) population during a period when the puma (Puma concolor) population was growing in the Black Hills, South Dakota, 2006–2018. We obtained survival data from 47 adult goats (n = 33 females, n = 14 males). Annual survival varied from 0.538 (95% CI [0.285–0.773]) to 1.00 (95% CI [1.00–1.00]) and puma predation was the primary cause-specific mortality factor over a 12-year period. Cumulative hectares of mountain pine beetle (Dendroctonus ponderosae) disturbance was a covariate of importance (wi = 0.972; β = 0.580, 95% CI [0.302–0.859]) influencing survival. To our knowledge, this is the first account of puma being the primary mortality factor of mountain goats over a long-term study. The Black Hills system is unique because we could examine the expanded realized niche of puma in the absence of other large carnivores and their influence on mountain goats. We hypothesize that puma were being sustained at higher densities due to alternate prey sources (e.g., white-tailed deer; Odocoileous virginianus) and this small population of mountain goats was susceptible to predation by one or several specialized puma in the Black Hills. However, we also hypothesize a changing landscape with increased tree mortality due to insect infestation provided conditions for better predator detection by goats and increased survival. Alternatively, open canopy conditions may have increased understory forage production potentially increasing mountain goat survival but we did not evaluate this relationship. Survival and mortality rates of mountain goats should continue to be monitored as this small population may be highly susceptible to population declines due to slow growth rates.

A small protected area facilitates persistence of a large carnivore in a ranching landscape

Assessments of the role that small (<500 km2) protected areas play in conservation of large carnivores in landscapes where the species are persecuted are scarce. Using camera-trap sampling we estimated puma (Puma concolor) population abundance, site use intensity, and relative abundance of prey in Lihué Calel National Park (320 km2) and two neighboring livestock ranches in central Argentina. We concurrently assessed rancher attitudes towards puma in relation to livestock predation by this carnivore and retaliation by ranchers in the ranching landscape surrounding the protected area. At least 3–8 adult pumas were recorded within the park while no individuals were detected on private ranchland. Site abundance within the park was positively related to the distance from the park boundary. The overall prey base inside and outside the park was similar. Sixteen out of 17 ranchers reported livestock losses due to puma predation and 76% of ranchers employed lethal control of carnivores to avoid livestock losses, resulting in 16 pumas killed during 2007–2009 in the surveyed ranches. The avoidance by pumas of the park´s border, the absence of puma detections on ranches, the similar prey availability inside and outside the park, and the positive association between rancher’s negative perceptions and persecution of pumas suggests that puma occurrence is depressed in ranchlands as a result of human-induced mortality. Our results demonstrate how small protected areas can play a role in maintaining large carnivores within productive landscapes despite harsh persecution. We emphasize the positive role of ranches that do not persecute pumas and the need to facilitate the coexistence between puma and people for the long term conservation of this felid in ranching landscapes.

The Elephant in the room: What can we learn from California regarding the use of sport hunting of pumas (Puma concolor) as a management tool?

Puma (Puma concolor) management in the western United States is highly contentious, particularly with regard to the use of sport hunting as a management tool. Since the 1970s, puma in ten western states have been managed by state fish and game agencies through the use of a sport hunt. The rationale presented by wildlife managers is that sport hunting, in addition to providing recreational hunting opportunities, also reduces threats to human safety and livestock safety, and increases populations of the puma’s ungulate prey, namely deer (Odocoileus sp.) and elk (Cervus elepus). We evaluated these claims using the state of California as a control, which has prohibited sport hunting since 1972, and employing data obtained from state and federal agencies with authority and control over puma management. Specifically, we tested four hypotheses: 1) sport hunting will suppress puma populations, 2) sport hunting will reduce the number of problematic puma-human encounters; 3) sport hunting will reduce puma predation on domestic livestock, and 4) sport hunting will reduce the impact of puma predation on wild ungulate numbers, resulting in increased hunting opportunities for the sport hunt of ungulates. Our results indicated, respectively, that relative to the 10 states where puma are hunted, California had 1) similar puma densities, 2) the 3rd lowest per capita problematic puma-human encounters, 3) similar per capita loss of cattle (P = 0.13) and a significantly lower (t = 5.7, P < 0.001) per capita loss of sheep, and 4) similar average deer densities while changes in annual deer populations correlated with changes in other states (F = 95.4, P < 0.001, R2 = 0.68). In sum, our analysis of the records obtained from state and federal wildlife agencies found no evidence that sport hunting of pumas has produced the management outcomes sought by wildlife managers aside from providing a sport hunting opportunity. Consequently, and particularly because other research suggests that sport hunting actually exacerbate conflicts between pumas and humans, we recommend that state agencies re-assess the use of sport hunting as a management tool for pumas.

FIRST OBSERVATION OF A PUMA (PUMA CONCOLOR) FEEDING ON A PINNIPED NEAR DEEP COVE, BRITISH COLUMBIA

Apex carnivores, including Pumas (Puma concolor), play a key role in ecological communities. Pumas have variable foraging patterns across their extensive range and are known scavengers. A recent review of Puma diet and predation studies documented a total of 48 mammal prey types representing 9 of the 13 orders found in North America, but excluding marine mammals (Orders Cetacea and Sirenia, and Clade Pinnipedimorpha) or tapirs (Order Perissodactyla). This report documents what is, to the best of our knowledge, the 1st observation of a Puma feeding on a marine mammal, a Harbor Seal (Phoca vitulina). Pinnipeds, as hunted or scavenged prey, could be a significant resource for Pumas in coastal areas and should be a focus of future studies. Novel observations of prey items, such as this, are important to document as they expand our understanding of apex carnivores and the effects they have on ecological communities.

Pumas affect elk dynamics in absence of other large carnivores

ABSTRACTWe investigated survival, reproduction, and population growth (λ) for a declining elk (Cervus canadensis nelsoni) population in South Dakota, USA, 2011–2015. We obtained survival data from 125 calves and 34 yearlings. We determined survival and pregnancy rates for 42 adults (2–8 years old) and 39 old adults (≥8 years old). We combined population vital rates into a matrix model, which indicated a slightly growing population but with considerable uncertainty ( = 1.03, 95% CI = 0.93–1.13). Our elasticity analysis suggested asymptotic growth rates were most sensitive to proportional changes in old adult and adult female survival, followed by proportional changes in calf and yearling survival. Our life‐stage simulation analysis further supported asymptotic growth rates being most sensitive to variation in survival, and most of the variation in λ we observed was a consequence of variation in annual calf survival (R2 = 0.58). Annual calf survival was low (0.26, 95% CI = 0.05–0.52), and puma (Puma concolor) predation was the primary cause‐specific mortality factor of calves (0.63, 95% CI = 0.51–0.76). Adult female survival was near its biological maximum (0.95, 95% CI = 0.87–0.99); therefore, managing for increased calf survival may be the most practical strategy for promoting elk population growth in this system. Managing this puma population at the lower end of the population objective and reducing white‐tailed deer (Odocoileous virginianus) numbers (primary prey source) may allow for elk population growth in this system. © 2017 The Wildlife Society.

QUANDO O PREDADOR SE TORNA PRESA: CONFLITO ENTRE FAZENDEIROS E A ONÇA-PARDA (Puma concolor, LINNAEUS, 1771) NO NORDESTE DO BRASIL

&lt;p&gt;A onça-parda, suçuarana ou puma (&lt;em&gt;Puma concolor&lt;/em&gt;, Linnaeus, 1771) é o segundo maior felino das Américas. Historicamente, a predação de puma a espécies domésticas gera conflitos com fazendeiros e leva ao aumento do controle letal incluindo a caça ilegal deste felino por fazendeiros locais. O puma é considerado uma espécie de preocupação para conservação no Brasil. No entanto, pouco se sabe sobre o estado da sua conservação ou a magnitude de suas predações de rebanhos domésticos. Para abordar esta informação, avaliamos: 1) o impacto de caça a &lt;em&gt;P. concolor&lt;/em&gt; em resposta tanto à predação de rebanhos domésticos quanto às variáveis como presença ou não de fragmento florestal preservado; 2) tamanho e manejo da criação, que estão associadas a tais eventos em propriedades da zona rural do município de Itaetê, Chapada Diamantina, Bahia, Brasil. Os dados foram obtidos mediante coleta de vestígios, como animais predados, pegadas e pele, como forma de auxiliar na comprovação da presença de &lt;em&gt;P. concolor &lt;/em&gt;na região. Para avaliar a percepção dos fazendeiros e seu impacto na pecuária, conduzimos entrevistas semiestruturadas entre novembro de 2013 e junho de 2014 a 24 gerentes e/ou proprietários das fazendas. Consideramos cada propriedade como uma unidade de análise independente. Das 24 fazendas visitadas, houve eventos de predação em 13, com mais de um ataque de uma única vez. Todos os informantes relataram que as predações acometem apenas os caprinos, tendo como predador principal a &lt;em&gt;P. concolor&lt;/em&gt;. Os Maiores números de animais predados ocorreram em fazendas onde o manejo era de confinamento noturno, contrariando a literatura. Por nossa área de estudo ter parte de seu território englobado pelo Parque Nacional da Chapada Diamantina, merece maior atenção. Para isso, torna-se necessária a implantação de medidas preventivas para minimizar os ataques e, assim, favorecer a conservação do felino na região.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Fear of the human 'super predator' reduces feeding time in large carnivores.

Large carnivores' fear of the human 'super predator' has the potential to alter their feeding behaviour and result in human-induced trophic cascades. However, it has yet to be experimentally tested if large carnivores perceive humans as predators and react strongly enough to have cascading effects on their prey. We conducted a predator playback experiment exposing pumas to predator (human) and non-predator control (frog) sounds at puma feeding sites to measure immediate fear responses to humans and the subsequent impacts on feeding. We found that pumas fled more frequently, took longer to return, and reduced their overall feeding time by more than half in response to hearing the human 'super predator'. Combined with our previous work showing higher kill rates of deer in more urbanized landscapes, this study reveals that fear is the mechanism driving an ecological cascade from humans to increased puma predation on deer. By demonstrating that the fear of humans can cause a strong reduction in feeding by pumas, our results support that non-consumptive forms of human disturbance may alter the ecological role of large carnivores.

Understanding rancher coexistence with jaguars and pumas: a typology for conservation practice

Ranchers living near large carnivores can adopt diverse practices to prevent livestock damage. Effective management interventions to help reduce damage must address the varied needs of ranchers by segmenting audiences for more targeted programs. We developed a typology that conceptualized six types of ranchers based on the theory of planned behavior. We posited that rancher types were driven by: attitudes; social norms; perceived control; emotional disposition; risk perception; and contextual factors. To test the typology throughout Costa Rica, we conducted a structured survey of a random sample of 93 ranchers affected by jaguar and puma predation and paired them with a sample of 69 unaffected neighbors. Cluster analyses of survey results provided empirical support for a typology of four types of ranchers, two of which were predicted by the theory of planned behavior: preventive ranchers who take control to prevent felid damage; and helpless ranchers who lack control. We also identified a risk-neutral type who takes no action as they do not perceive the cats as a threat; and a cat-troubled type influenced mainly by negative emotions toward big cats. This last type supports the need to include emotional factors in theoretical frameworks when dealing with human-wildlife conflict. The typology is useful for designing improved policy and management interventions to reduce wildlife conflicts.

Stage‐dependent puma predation on dangerous prey

AbstractPredators likely assess their risk of injury with regards to hunting different prey types, while deciding whether to initiate an attack or to avoid dangerous prey. Risk‐taking is age‐, stage‐ and state‐dependent, and foraging theory predicts that juvenile predators, individuals of lower social rank, and less‐experienced predators that are hungry are among those most likely to engage dangerous prey. In carnivores that optimally hunt prey larger than themselves, however, juveniles may also select for smaller, suboptimal prey as they refine their hunting skills. Thus, in the case of predators that exhibit age‐specific prey selection, there may be multiple factors influencing decision‐making about prey selection. We compared puma (Puma concolor) predation on dangerous adult ungulates and safer juvenile ungulates, as well as two similar‐sized rodent species: the more dangerous North American porcupine (Erethizon dorsatum) and the more vulnerable American beaver (Castor canadensis). We found that dispersing, subadult pumas with limited hunting experience and without territories avoided dangerous but optimally sized adult ungulates, and instead hunted dangerous, suboptimal porcupines more than resident, territorial adults. In contrast, there was no difference in puma predation on beavers between dispersers and residents. Small prey (e.g. not ungulates) formed a large portion of dispersing puma diets of both sexes, and this stage‐dependent foraging pattern might be important in describing the ecology of the species, as well as in modeling potential dispersal habitat that could see puma expansion east in North America across hostile matrices where their primary prey has been reduced through anthropogenic effects.

Puma predation subsidizes an obligate scavenger in the high Andes

SummaryThe ungulate–carnivore–vulture complex is a key trophic module of many terrestrial ecosystems, but one that is globally under threat. Few have explored cross‐species dependencies in this module, and the degree to which vultures rely on trophic facilitation by apex carnivores is rarely known and almost never quantified.We investigated the importance of pumaPuma concolorpredation on its native camelid prey, vicuñasVicugna vicugnaand guanacosLama guanicoe, in food provisioning for Andean condorsVultur gryphusin the high Andes of north‐western Argentina. We evaluated the origin of wild food sources through carcass surveys. We quantified condor feeding habits via foraging observations and through the analysis of pellet contents and stable isotopes from moulted feathers.Of the 102 fresh camelid carcasses we monitored, nearly all (94%) resulted from puma predation, and the majority (85%) of camelid carcasses used by condors were killed by pumas. Camelids represented 88% of the prey items identified from 183 condor pellets, and isotopic analyses of moulted feathers from 86 individuals identified via multilocus genotyping revealed that camelids and Small livestock were the most important prey items, representing 45–58% and 28–38% of condor assimilated biomass, respectively.Synthesis and applications. Our results show that puma predation plays a key role in the foraging ecology of Andean condors, and highlight the importance of predatory processes that make carrion available to scavengers. We contend that targeting the conservation of ungulate–carnivore–vulture modules, rather than a species‐specific approach, will be a more effective strategy to ensure the long‐term persistence of Andean condors and other obligate scavengers.

Compensatory puma predation on adult female mule deer in New Mexico

Pumas ( Puma concolor ) are the primary predator of adult mule deer ( Odocoileus hemionus ) throughout most of arid New Mexico, and predation by pumas is popularly believed to limit mule deer populations. Predation can limit population size of prey if it is primarily additive or acts in addition to other mortality factors. Thus, clarifying the impact of predation is important because of misconceptions regarding the act of predation (i.e., killing an individual) rather than the effect (i.e., effects on population demography) cloud discussions of the issue. Herein, we tested the population-level question of whether puma predation on adult female mule deer is compensatory or additive mortality in multiple mule deer populations in New Mexico. We modeled annual survival rate as a function of cause-specific mortality rate. For this conservative test, a slope = 0 indicated complete compensation, whereas a slope = −1 indicated complete additivity. For all populations, the corrected slope of predation ultimately attributable to pumas was 0.00, ultimate and proximate puma predation combined was 0.10, ultimate puma predation and unknown causes of mortality combined was −0.28, and ultimate and proximate puma predation and unknown deaths combined was −0.23. Thus, puma predation appeared primarily compensatory. Despite small sample sizes, individual populations showed similar patterns indicating the compensatory nature of puma predation. Primarily compensatory predation for mule deer reflected the relatively low condition of deer. Survival was most strongly tied to individual condition in these populations, and a priori condition of puma-predated mule deer was lower than the population means. Compensatory mortality requires predisposition whether caused by decreased condition, high population density, or other factors. If conditions that predispose individual deer to mortality are present, managers should not assume that predation is limiting, regardless of predation rates.

Puma (Puma concolor) predation on tapir (Tapirus terrestris)

The process of forest fragmentation affects mostly top predators, which are more prone to first disappear. Pumas, Puma concolor, are known to have a generalist diet that includes a wide variety of wild and domestic prey species. The capacity of adapting their diet to consuming prey in anthropogenic habitats may be the reason for this species' success in incorporating anthropogenic areas with different levels of fragmentation as part of its habitat. Here we report a case of puma consumption of a large wild prey species, the tapir, Tapirus terrestris. From March 2012 to October 2013 we collected 85 puma's scats opportunistically inside fragments of the Atlantic Forest in the Parana state, Brazil. In one of the scats we found hairs and some hooves of a tapir, as well as puma hairs. We propose two hypotheses that may explain the occurrence of tapir in a pumás scat: (1) an event of scavenging or (2) an event of predation on a juvenile tapir. The most likely explanation for this event may be the predation of a juvenile in response to a possible abundant presence of tapirs in the study area. This event adds to our understanding of the great plasticity of this species to adapt to an altered landscape. To our knowledge, this is the first report of a puma scavenging or predation event on a tapir.

Elk resource selection at parturition sites, Black Hills, South Dakota

We studied elk (Cervus canadensis nelsoni) parturition sites at coarse (314-km2 and 7-km2) and fine (0.2-ha) scales in the Black Hills, South Dakota, 2011–2013, following a period of population decline and poor calf recruitment. Our objective was to test whether female elk selected parturition sites across spatial scales in association with forage, terrain ruggedness, road density, or hiding and security cover. At coarse scales in forests and grasslands, female elk selected sites in areas with greater proportions of vegetation communities that provided forage (56–74% of area) and more rugged topography (194–248 m) than found at random. At coarse scales in grasslands, elk selected sites in areas with lower road densities (≤1.24 km/plot). At the fine scale in forests and grasslands, female elk selected sites in areas with intermediate slope (19%), closer to water (355–610 m), and far from roads (541–791 m). Further, elk in forests and grasslands selected sites with intermediate security cover (50–88 m). We hypothesize elk selected for intermediate rugged terrain at larger scales for security from high road densities and human disturbance, but these areas may have placed elk in riskier environments for puma (Puma concolor) predation. Forest management that maintains open-canopied vegetation communities in less rugged areas and prevents ponderosa pine (Pinus ponderosa) encroachment of meadows to provide forage may be beneficial for elk. Further, elk parturition sites occurred close to roads, particularly on public lands, and agencies should consider road-use restrictions and vegetation buffers beside roads in areas with less rugged terrain, which may provide favorable calving habitat. © 2015 The Wildlife Society.

Home sweet home: fitness consequences of site familiarity in female black-tailed deer

Individual animals strive to maximize fitness by gaining access to food while minimizing predation risk, and spatial knowledge of both forage resources and predation risks has long been presumed to be advantageous. Actual fitness benefits of site familiarity, however, have rarely been demonstrated. We placed GPS collars on 57 female black-tailed deer in coastal California over 4 years to track seasonal movements, determine home ranges, and monitor survival and cause of mortality. We used seasonal home ranges and core areas as measures of site familiarity and modeled how mortality risk varied with use of familiar areas, forage availability, age class, and elevational overlap with simultaneously collared pumas using Cox proportional hazards models. The use of familiar areas was the best predictor of mortality risk, and deer that had a 40 % probability of leaving their home range in a given week were four times more likely to die. Puma predation was the largest cause of mortality, and deer whose average weekly elevation was farther from the average elevation of pumas were less likely to die. While forage availability was not related to mortality risk, deer with lower forage availability were more likely to leave their home range during both summer and winter. Our results provide a rare example of fitness benefits associated with site familiarity and the use of familiar areas as a refuge from predation. The benefits of site familiarity are likely widespread in ungulates, especially when there are stable home ranges, complex habitats, and few cues of predation risk.

Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions

AbstractAccording to current theory, anti‐predator benefits promote group formation in open‐dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti‐predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual. To test this hypothesis, group‐size effects on female time allocation and within‐group aggression rate were compared between two guanaco populations exposed to contrasting levels of puma predation. Habitat structure within both sites consisted of mosaics of shrublands and grasslands, and group‐size effects were also compared between these habitat types. Females under predation risk showed a strong reduction in vigilance as the number of adults in the group increased, whereas females from the predator‐free population showed overall low levels of vigilance, regardless of group size. These results emphasize the anti‐predator significance of the group‐size effect on female vigilance, as well as guanaco plasticity to adjust time allocation to local conditions. On the other hand, within‐group aggression rate increased with the number of adults in the group. Aggression rate was almost null within groups located in grasslands but was significantly higher in shrublands, regardless of predation risk, suggesting that the more heterogeneous distribution of shrubs increases the interference competition level. These results strengthen the notion of predation pressure and habitat structure as major determinants of the balance between costs and benefits of group living, and highlight the potential of individual behavioral patterns to make qualitative predictions about group‐size variation within territorial ungulates.

Evaluating a potentially strong trophic interaction: pumas and wild camelids in protected areas of Argentina

Predatory interactions involving large carnivores and their ungulate prey are increasingly recognized as important in structuring terrestrial communities, but such interactions have seldom been studied in the temperate Neotropics. Here, the large carnivore guild is limited to a single species, the puma Puma concolor, native prey populations have been drastically reduced and lagomorphs and ungulates have been introduced. We examined puma dietary patterns under varying abundances of native camelid prey – guanacos and vicu ˜ nas – in protected areas of northwestern Argentina. We collected puma feces from seven protected areas, and sampled each area for the relative abundance of camelids using on-foot strip and vehicle transects. In one area, where longitudinal studies have been conducted, we examined the remains of vicu ˜ nas and guanacos for evidence of puma predation in 2004–2006. We compared our results with a study conducted in 1978–1983, and contrasted the frequency of carcasses showing signs of puma predation with estimates of camelid abundance. Across sites, we observed a positive and significant relationship between camelid consumption by pumas and camelid abundance, with pumas about nine times more likely to consume camelids where the latter were most abundant. The temporal variation in predation rates on camelids differed by species. Guanacos, which did not change in abundance between periods, showed a slight decrease (1.5 times) in the relative frequencies of individuals killed by pumas. Conversely, vicu ˜ nas increased in abundance by a factor of � 7 between periods, coinciding with an c. 3.4 times increase in individuals showing evidence of puma predation. Some protected areas of northwestern Argentina are conserving the trophic interaction between pumas and native camelid prey. This interaction may be the basis of the far-reaching community effects described for analogous systems on other continents. It also has implications for the possible recovery of or reintroduction of camelids to areas with high puma densities, where predation losses can be expected to be high, and possibly prohibitive.

Puma predation on radiocollared and uncollared bighorn sheep

BackgroundWe used Global Positioning System (GPS) data from radiocollared pumas (Puma concolor) to identify kill sites of pumas preying upon an endangered population of bighorn sheep (Ovis canadensis) in southern California. Our aims were to test whether or not pumas selected radiocollared versus uncollared bighorn sheep, and to identify patterns of movement before, during, and after kills.FindingsThree pumas killed 23 bighorn sheep over the course of the study, but they did not preferentially prey on marked (radiocollared) versus unmarked bighorn sheep. Predation occurred primarily during crepuscular and nighttime hours, and 22 kill sites were identified by the occurrence of 2 or more consecutive puma GPS locations (a cluster) within 200 m of each other at 1900, 0000, and 0600 h.ConclusionWe tested the "conspicuous individual hypothesis" and found that there was no difference in puma predation upon radiocollared and uncollared bighorn sheep. Pumas tended to move long distances before and after kills, but their movement patterns immediately post-kill were much more restricted. Researchers can exploit this behaviour to identify puma kill sites and investigate prey selection by designing studies that detect puma locations that are spatially clustered between dusk and dawn.